In the recent field of radiocommunication system, radiocommunication systems have been developed which adopt the “Bluetooth” (will be referred to as “BT” hereunder) system for data transfer between communication devices by frequency hopping of a radio wave included in a 2.4 GHz band.
The “BT” is a code name of a new industrial standard for implementation of radiocommunication between devices such as a mobile device, computer, hand-held computing device, mobile telephone, head set and a wearable computer, PC peripheral devices such as a printer etc., and human interface devices such as data pad, mouse, etc. The BT system has been developed through a collaboration of telecommunication, networking and similar industries to implement an ad-hoc radio frequency (RF) networking between a plurality of personal computers and devices. The BT system was developed by the Intel, Ericsson, IBM, Nokia and Toshiba (registered trademarks) joining the BT SIG (special interest group) Owing to the BT system, a notebook computer, PDA (personal digital assistant) or mobile telephone can share information and various services with a personal computer by a radiocommunication, and thus there is no necessity for any troublesome cable connection between them. For the BT system, standards for radiocommunication interface and control software were established to assure an interoperability between the devices, and they are disclosed in the “BT (trademark) Special Interest Group, BT Specification Version 1.0”.
Referring now to FIG. 1, there is schematically illustrated the whole construction of a conventional radiocommunication system adopting the BT system. The radiocommunication system is indicated with a reference 100. As shown, this radiocommunication system 100 includes a mobile telephone 101, personal computer 102, digital camera 103 and a personal digital assistant (PDA) 104, each having a radiocommunication module 110 by which they are enabled to make mutual data communications with each other.
Also, for dial-up access from the mobile telephone 101 in the radiocommunication system 100 to an Internet network 300 via a mobile network 200, the mobile telephone 101 is connected by the personal computer 102, digital camera 103 and PDA 104 to an Internet service provider 301 in the Internet network 300, and to a WWW (worldwide web) server 302 in the Internet network 300, via the radiocommunication system 100 and mobile network 200.
Thus, the radiocommunication system 100 enables the personal computer 102, digital camera 103 and PDA 104 to wirelessly connect to the Internet network 300, not via the mobile telephone 101 and any cable. Therefore, the radiocommunication system 100 permits to improve the portability of the personal computer 102, digital camera 103 and PDA 104. Also, the radiocommunication system 100 enables the user or subscriber to access the Internet network 300 holding only a terminal like the PDA 104 in hand with the mobile telephone 101 being kept in his or her bag or the like.
Next, the construction of a host device 500 included in the radiocommunication system 100 will be described with reference to FIG. 2. The host device 500 corresponds to the personal computer 102, digital camera 103 or PDA 104 shown in FIG. 1.
As shown in FIG. 2, the host device 500 includes a radiocommunication module 510 corresponding to the radiocommunication module 110 and which controls communication with the outside, and a host controller 530 which controls the host device 500 itself.
The radiocommunication module 510 includes a radiocommunication unit 511 to control radiocommunication within the radiocommunication system 100, an antenna 512 for data communication with each of the components of the radiocommunication system 100, a base-band controller 513 to control the radiocommunication unit 511, and an interface 514 connected by a cable to the host controller 530 for data input and output.
The base-band controller 513 provides a control over the radiocommunication unit 511, including frequency hopping control. Also, the base-band controller 513 converts data to a predetermined format for sending via the radiocommunication module 510, while converting received data in the predetermined format for output to the host controller 530.
The radiocommunication unit 511 includes a receiver 521 to receive radio data from the antenna 512, transmitter 522 to send radio data from the antenna 512, switch 523 to select whether radio data from the transmitter 522 should be sent via the antenna 512 or radio data from the antenna 512 should be provided to the receiver 521, and a hopping synthesizer 524 to generate a local frequency for use in the receiver 521 and transmitter 522 and spread the spectrum by the frequency hopping.
The radiocommunication module 510 further includes a RAM (random-access memory) 516, ROM (read-only memory) 517 and a CPU (central processing unit) 518, each connected to a system bus 515 composed of an address bus and data bus.
The CPU 518 reads, from the ROM 517 via the system bus 515, a control program intended to control each of the components of the radiocommunication module 510, to generate a control signal for controlling each component. At this time, the CPU 518 stores data in the RAM 516 as a work area as necessary to execute the control program. Thereby, the CPU 158 controls the base-band controller 513 and radiocommunication unit 511 to control radiocommunication with other devices included in the radiocommunication system 100, while sending and receiving user data to and from the host controller 530 via the interface 514.
The host controller 530 in the host device 500 includes an interface 531 for input and output of signals from and to the interface 514 in the radiocommunication module 510, a network setting storage 533 to store network setting information such as server address etc. of the Internet service provider 301 when the host device 500 is connected to the Internet, a personal information storage 534 to store personal information such as user ID, mail address, password, etc of each user having the host device 500, and a CPU 535 to control each of these components of the host controller 530. These components of the host controller 530 are connected to a system bus 532. The host controller 530 further includes a power supply 536 which supplies a power to the radiocommunication module 510.
For connection between the host device 500 and Internet network 300, network setting information stored in the network setting information storage 533 and personal information stored in the personal information storage 534 are first provided to the radiocommunication module 510, and then the radiocommunication unit 511 and base-band controller 513 are controlled to make a setting for connection to the Internet network 300 by the CPU 518 in the radiocommunication module 510 by the use of the network setting information and personal information, to thereby establish a connection between the host device 500 and WWW server 302.
For addition of the BT-based radiocommunication function to each component, the latter has to incorporate the radiocommunication module 510 having a BT radiocommunication function. FIG. 3 shows protocol stacks 610 and 620 for the mobile telephone 101 and PDA 104 each having the radiocommunication module 510.
As shown, each of the protocol stacks 610 and 620 has five layers as lower layers to implement the BT-based radiocommunication system 100, including an RF layer for FH and data communications in the 2.4 GHz band, BB (base-band) layer for base-band control, LMP (link manager protocol) layer for handling including connection, disconnection and link, L2CAP (logical link control and adaptation protocol) layer for multiplexing, segmentation and decomposition of various protocols, and RFCOMM layer being a simple transport protocol to emulate the RS-232C serial line.
The mobile telephone 101 and PDA 104 use these five layers for data communications inside the radiocommunication system 100.
Also, the protocol stack 620 has provided above the RFCOMM layer thereof a PPP (point to point protocol) used for dial-up connection to the Internet network 300, an IP (Internet protocol) required for connection to the Internet network 300 and a TCP (transmission control protocol). These protocols are used to send and receive data to and from an application layer (AP).
As in the above, the protocol stack 610 provided in the mobile telephone 101 has the lower five layers similar to those in the protocol stack 620 to implement the BT-based radiocommunication system 100. It also has provided above the RFCOMM layer thereof a data communication mode layer for connection to the mobile network 200. The data communication mode layer includes data communication mode layers for mobile telephone such as a CDMA-ONE (code division multiple access-ONE), W-CDMA (wideband-code division multiple access), etc. Thus, the radiocommunication system 100 uses the higher four layers of the PDA 104 to encapsulate the data by TCP/IP data and sends TCP/IP-encapsulated data to the PDA 104 by the use of the lower five layers, while encapsulating data by TCP/IP received via the mobile telephone 101 to make a connection to the Internet network 300 via the mobile network 200.
However, the method for constructing the radiocommunication system 100 as in the above is not advantageous as will be described below.
That is, an Internet protocol stack (TCP/IP, PPP) to enable a connection to the Internet network 300 via the radiocommunication system 100 has to be installed in the mobile telephone 101, PDA 104, etc. included in the radiocommunication system 100, which will cause the hardware of each of these devices 102 to 104 and software for them to be larger and thus complicate the construction of each of the devices 102 to 104. The Internet protocol stack adds to the costs of manufacturing the devices 102 to 104, and it often is a redundant design for the users who will not access the Internet network 300, for example.
Furthermore, the devices 102 to 104 included in the radiocommunication system 100 as shown in FIG. 2 have to store the network setting information such as address, mail address, password, etc. of the Internet service provider 301 and the personal information in the network setting information storage 533 and personal information storage 534, respectively, since such information is required for access to the Internet network 300.
Therefore, the user has to set network setting information and personal information for each of the devices 102 to 104. With a small portable device having only a man-machine interface function which is not sufficient, the setting of such network setting information and personal information will be very troublesome to the user of such a device. Thus, for easier setting of various information, a complicate man-machine interface has to be installed in each of the devices 102 to 104.
Among others, when selecting another Internet service provider 301, settings for access to the network have to be changed for each of the devices 102 to 104 included in the radiocommunication system 100.